/* * OMAP2 McSPI controller driver * * Copyright (C) 2005, 2006 Nokia Corporation * Author: Samuel Ortiz <samuel.ortiz@nokia.com> and * Juha Yrj�l� <juha.yrjola@nokia.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <linux/kernel.h> #include <linux/interrupt.h> #include <linux/module.h> #include <linux/device.h> #include <linux/delay.h> #include <linux/dma-mapping.h> #include <linux/dmaengine.h> #include <linux/pinctrl/consumer.h> #include <linux/platform_device.h> #include <linux/err.h> #include <linux/clk.h> #include <linux/io.h> #include <linux/slab.h> #include <linux/pm_runtime.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/gcd.h> #include <linux/spi/spi.h> #include <linux/gpio.h> #include <linux/platform_data/spi-omap2-mcspi.h> #define OMAP2_MCSPI_MAX_FREQ 48000000 #define OMAP2_MCSPI_MAX_DIVIDER 4096 #define OMAP2_MCSPI_MAX_FIFODEPTH 64 #define OMAP2_MCSPI_MAX_FIFOWCNT 0xFFFF #define SPI_AUTOSUSPEND_TIMEOUT 2000 #define OMAP2_MCSPI_REVISION 0x00 #define OMAP2_MCSPI_SYSSTATUS 0x14 #define OMAP2_MCSPI_IRQSTATUS 0x18 #define OMAP2_MCSPI_IRQENABLE 0x1c #define OMAP2_MCSPI_WAKEUPENABLE 0x20 #define OMAP2_MCSPI_SYST 0x24 #define OMAP2_MCSPI_MODULCTRL 0x28 #define OMAP2_MCSPI_XFERLEVEL 0x7c /* per-channel banks, 0x14 bytes each, first is: */ #define OMAP2_MCSPI_CHCONF0 0x2c #define OMAP2_MCSPI_CHSTAT0 0x30 #define OMAP2_MCSPI_CHCTRL0 0x34 #define OMAP2_MCSPI_TX0 0x38 #define OMAP2_MCSPI_RX0 0x3c /* per-register bitmasks: */ #define OMAP2_MCSPI_IRQSTATUS_EOW BIT(17) #define OMAP2_MCSPI_MODULCTRL_SINGLE BIT(0) #define OMAP2_MCSPI_MODULCTRL_MS BIT(2) #define OMAP2_MCSPI_MODULCTRL_STEST BIT(3) #define OMAP2_MCSPI_CHCONF_PHA BIT(0) #define OMAP2_MCSPI_CHCONF_POL BIT(1) #define OMAP2_MCSPI_CHCONF_CLKD_MASK (0x0f << 2) #define OMAP2_MCSPI_CHCONF_EPOL BIT(6) #define OMAP2_MCSPI_CHCONF_WL_MASK (0x1f << 7) #define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY BIT(12) #define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY BIT(13) #define OMAP2_MCSPI_CHCONF_TRM_MASK (0x03 << 12) #define OMAP2_MCSPI_CHCONF_DMAW BIT(14) #define OMAP2_MCSPI_CHCONF_DMAR BIT(15) #define OMAP2_MCSPI_CHCONF_DPE0 BIT(16) #define OMAP2_MCSPI_CHCONF_DPE1 BIT(17) #define OMAP2_MCSPI_CHCONF_IS BIT(18) #define OMAP2_MCSPI_CHCONF_TURBO BIT(19) #define OMAP2_MCSPI_CHCONF_FORCE BIT(20) #define OMAP2_MCSPI_CHCONF_FFET BIT(27) #define OMAP2_MCSPI_CHCONF_FFER BIT(28) #define OMAP2_MCSPI_CHCONF_CLKG BIT(29) #define OMAP2_MCSPI_CHSTAT_RXS BIT(0) #define OMAP2_MCSPI_CHSTAT_TXS BIT(1) #define OMAP2_MCSPI_CHSTAT_EOT BIT(2) #define OMAP2_MCSPI_CHSTAT_TXFFE BIT(3) #define OMAP2_MCSPI_CHCTRL_EN BIT(0) #define OMAP2_MCSPI_CHCTRL_EXTCLK_MASK (0xff << 8) #define OMAP2_MCSPI_WAKEUPENABLE_WKEN BIT(0) /* We have 2 DMA channels per CS, one for RX and one for TX */ struct omap2_mcspi_dma { struct dma_chan *dma_tx; struct dma_chan *dma_rx; struct completion dma_tx_completion; struct completion dma_rx_completion; char dma_rx_ch_name[14]; char dma_tx_ch_name[14]; }; /* use PIO for small transfers, avoiding DMA setup/teardown overhead and * cache operations; better heuristics consider wordsize and bitrate. */ #define DMA_MIN_BYTES 160 /* * Used for context save and restore, structure members to be updated whenever * corresponding registers are modified. */ struct omap2_mcspi_regs { u32 modulctrl; u32 wakeupenable; struct list_head cs; }; struct omap2_mcspi { struct spi_master *master; /* Virtual base address of the controller */ void __iomem *base; unsigned long phys; /* SPI1 has 4 channels, while SPI2 has 2 */ struct omap2_mcspi_dma *dma_channels; struct device *dev; struct omap2_mcspi_regs ctx; int fifo_depth; unsigned int pin_dir:1; }; struct omap2_mcspi_cs { void __iomem *base; unsigned long phys; int word_len; u16 mode; struct list_head node; /* Context save and restore shadow register */ u32 chconf0, chctrl0; }; static inline void mcspi_write_reg(struct spi_master *master, int idx, u32 val) { struct omap2_mcspi *mcspi = spi_master_get_devdata(master); writel_relaxed(val, mcspi->base + idx); } static inline u32 mcspi_read_reg(struct spi_master *master, int idx) { struct omap2_mcspi *mcspi = spi_master_get_devdata(master); return readl_relaxed(mcspi->base + idx); } static inline void mcspi_write_cs_reg(const struct spi_device *spi, int idx, u32 val) { struct omap2_mcspi_cs *cs = spi->controller_state; writel_relaxed(val, cs->base + idx); } static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx) { struct omap2_mcspi_cs *cs = spi->controller_state; return readl_relaxed(cs->base + idx); } static inline u32 mcspi_cached_chconf0(const struct spi_device *spi) { struct omap2_mcspi_cs *cs = spi->controller_state; return cs->chconf0; } static inline void mcspi_write_chconf0(const struct spi_device *spi, u32 val) { struct omap2_mcspi_cs *cs = spi->controller_state; cs->chconf0 = val; mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, val); mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0); } static inline int mcspi_bytes_per_word(int word_len) { if (word_len <= 8) return 1; else if (word_len <= 16) return 2; else /* word_len <= 32 */ return 4; } static void omap2_mcspi_set_dma_req(const struct spi_device *spi, int is_read, int enable) { u32 l, rw; l = mcspi_cached_chconf0(spi); if (is_read) /* 1 is read, 0 write */ rw = OMAP2_MCSPI_CHCONF_DMAR; else rw = OMAP2_MCSPI_CHCONF_DMAW; if (enable) l |= rw; else l &= ~rw; mcspi_write_chconf0(spi, l); } static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable) { struct omap2_mcspi_cs *cs = spi->controller_state; u32 l; l = cs->chctrl0; if (enable) l |= OMAP2_MCSPI_CHCTRL_EN; else l &= ~OMAP2_MCSPI_CHCTRL_EN; cs->chctrl0 = l; mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0); /* Flash post-writes */ mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0); } static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable) { struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master); u32 l; /* The controller handles the inverted chip selects * using the OMAP2_MCSPI_CHCONF_EPOL bit so revert * the inversion from the core spi_set_cs function. */ if (spi->mode & SPI_CS_HIGH) enable = !enable; if (spi->controller_state) { int err = pm_runtime_get_sync(mcspi->dev); if (err < 0) { pm_runtime_put_noidle(mcspi->dev); dev_err(mcspi->dev, "failed to get sync: %d\n", err); return; } l = mcspi_cached_chconf0(spi); if (enable) l &= ~OMAP2_MCSPI_CHCONF_FORCE; else l |= OMAP2_MCSPI_CHCONF_FORCE; mcspi_write_chconf0(spi, l); pm_runtime_mark_last_busy(mcspi->dev); pm_runtime_put_autosuspend(mcspi->dev); } } static void omap2_mcspi_set_master_mode(struct spi_master *master) { struct omap2_mcspi *mcspi = spi_master_get_devdata(master); struct omap2_mcspi_regs *ctx = &mcspi->ctx; u32 l; /* * Setup when switching from (reset default) slave mode * to single-channel master mode */ l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL); l &= ~(OMAP2_MCSPI_MODULCTRL_STEST | OMAP2_MCSPI_MODULCTRL_MS); l |= OMAP2_MCSPI_MODULCTRL_SINGLE; mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l); ctx->modulctrl = l; } static void omap2_mcspi_set_fifo(const struct spi_device *spi, struct spi_transfer *t, int enable) { struct spi_master *master = spi->master; struct omap2_mcspi_cs *cs = spi->controller_state; struct omap2_mcspi *mcspi; unsigned int wcnt; int max_fifo_depth, fifo_depth, bytes_per_word; u32 chconf, xferlevel; mcspi = spi_master_get_devdata(master); chconf = mcspi_cached_chconf0(spi); if (enable) { bytes_per_word = mcspi_bytes_per_word(cs->word_len); if (t->len % bytes_per_word != 0) goto disable_fifo; if (t->rx_buf != NULL && t->tx_buf != NULL) max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH / 2; else max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH; fifo_depth = gcd(t->len, max_fifo_depth); if (fifo_depth < 2 || fifo_depth % bytes_per_word != 0) goto disable_fifo; wcnt = t->len / bytes_per_word; if (wcnt > OMAP2_MCSPI_MAX_FIFOWCNT) goto disable_fifo; xferlevel = wcnt << 16; if (t->rx_buf != NULL) { chconf |= OMAP2_MCSPI_CHCONF_FFER; xferlevel |= (fifo_depth - 1) << 8; } if (t->tx_buf != NULL) { chconf |= OMAP2_MCSPI_CHCONF_FFET; xferlevel |= fifo_depth - 1; } mcspi_write_reg(master, OMAP2_MCSPI_XFERLEVEL, xferlevel); mcspi_write_chconf0(spi, chconf); mcspi->fifo_depth = fifo_depth; return; } disable_fifo: if (t->rx_buf != NULL) chconf &= ~OMAP2_MCSPI_CHCONF_FFER; if (t->tx_buf != NULL) chconf &= ~OMAP2_MCSPI_CHCONF_FFET; mcspi_write_chconf0(spi, chconf); mcspi->fifo_depth = 0; } static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit) { unsigned long timeout; timeout = jiffies + msecs_to_jiffies(1000); while (!(readl_relaxed(reg) & bit)) { if (time_after(jiffies, timeout)) { if (!(readl_relaxed(reg) & bit)) return -ETIMEDOUT; else return 0; } cpu_relax(); } return 0; } static void omap2_mcspi_rx_callback(void *data) { struct spi_device *spi = data; struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master); struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select]; /* We must disable the DMA RX request */ omap2_mcspi_set_dma_req(spi, 1, 0); complete(&mcspi_dma->dma_rx_completion); } static void omap2_mcspi_tx_callback(void *data) { struct spi_device *spi = data; struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master); struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select]; /* We must disable the DMA TX request */ omap2_mcspi_set_dma_req(spi, 0, 0); complete(&mcspi_dma->dma_tx_completion); } static void omap2_mcspi_tx_dma(struct spi_device *spi, struct spi_transfer *xfer, struct dma_slave_config cfg) { struct omap2_mcspi *mcspi; struct omap2_mcspi_dma *mcspi_dma; unsigned int count; mcspi = spi_master_get_devdata(spi->master); mcspi_dma = &mcspi->dma_channels[spi->chip_select]; count = xfer->len; if (mcspi_dma->dma_tx) { struct dma_async_tx_descriptor *tx; dmaengine_slave_config(mcspi_dma->dma_tx, &cfg); tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, xfer->tx_sg.sgl, xfer->tx_sg.nents, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (tx) { tx->callback = omap2_mcspi_tx_callback; tx->callback_param = spi; dmaengine_submit(tx); } else { /* FIXME: fall back to PIO? */ } } dma_async_issue_pending(mcspi_dma->dma_tx); omap2_mcspi_set_dma_req(spi, 0, 1); } static unsigned omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer, struct dma_slave_config cfg, unsigned es) { struct omap2_mcspi *mcspi; struct omap2_mcspi_dma *mcspi_dma; unsigned int count, transfer_reduction = 0; struct scatterlist *sg_out[2]; int nb_sizes = 0, out_mapped_nents[2], ret, x; size_t sizes[2]; u32 l; int elements = 0; int word_len, element_count; struct omap2_mcspi_cs *cs = spi->controller_state; void __iomem *chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0; mcspi = spi_master_get_devdata(spi->master); mcspi_dma = &mcspi->dma_channels[spi->chip_select]; count = xfer->len; /* * In the "End-of-Transfer Procedure" section for DMA RX in OMAP35x TRM * it mentions reducing DMA transfer length by one element in master * normal mode. */ if (mcspi->fifo_depth == 0) transfer_reduction = es; word_len = cs->word_len; l = mcspi_cached_chconf0(spi); if (word_len <= 8) element_count = count; else if (word_len <= 16) element_count = count >> 1; else /* word_len <= 32 */ element_count = count >> 2; if (mcspi_dma->dma_rx) { struct dma_async_tx_descriptor *tx; dmaengine_slave_config(mcspi_dma->dma_rx, &cfg); /* * Reduce DMA transfer length by one more if McSPI is * configured in turbo mode. */ if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0) transfer_reduction += es; if (transfer_reduction) { /* Split sgl into two. The second sgl won't be used. */ sizes[0] = count - transfer_reduction; sizes[1] = transfer_reduction; nb_sizes = 2; } else { /* * Don't bother splitting the sgl. This essentially * clones the original sgl. */ sizes[0] = count; nb_sizes = 1; } ret = sg_split(xfer->rx_sg.sgl, xfer->rx_sg.nents, 0, nb_sizes, sizes, sg_out, out_mapped_nents, GFP_KERNEL); if (ret < 0) { dev_err(&spi->dev, "sg_split failed\n"); return 0; } tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, sg_out[0], out_mapped_nents[0], DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (tx) { tx->callback = omap2_mcspi_rx_callback; tx->callback_param = spi; dmaengine_submit(tx); } else { /* FIXME: fall back to PIO? */ } } dma_async_issue_pending(mcspi_dma->dma_rx); omap2_mcspi_set_dma_req(spi, 1, 1); wait_for_completion(&mcspi_dma->dma_rx_completion); for (x = 0; x < nb_sizes; x++) kfree(sg_out[x]); if (mcspi->fifo_depth > 0) return count; /* * Due to the DMA transfer length reduction the missing bytes must * be read manually to receive all of the expected data. */ omap2_mcspi_set_enable(spi, 0); elements = element_count - 1; if (l & OMAP2_MCSPI_CHCONF_TURBO) { elements--; if (!mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS)) { u32 w; w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0); if (word_len <= 8) ((u8 *)xfer->rx_buf)[elements++] = w; else if (word_len <= 16) ((u16 *)xfer->rx_buf)[elements++] = w; else /* word_len <= 32 */ ((u32 *)xfer->rx_buf)[elements++] = w; } else { int bytes_per_word = mcspi_bytes_per_word(word_len); dev_err(&spi->dev, "DMA RX penultimate word empty\n"); count -= (bytes_per_word << 1); omap2_mcspi_set_enable(spi, 1); return count; } } if (!mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS)) { u32 w; w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0); if (word_len <= 8) ((u8 *)xfer->rx_buf)[elements] = w; else if (word_len <= 16) ((u16 *)xfer->rx_buf)[elements] = w; else /* word_len <= 32 */ ((u32 *)xfer->rx_buf)[elements] = w; } else { dev_err(&spi->dev, "DMA RX last word empty\n"); count -= mcspi_bytes_per_word(word_len); } omap2_mcspi_set_enable(spi, 1); return count; } static unsigned omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer) { struct omap2_mcspi *mcspi; struct omap2_mcspi_cs *cs = spi->controller_state; struct omap2_mcspi_dma *mcspi_dma; unsigned int count; u32 l; u8 *rx; const u8 *tx; struct dma_slave_config cfg; enum dma_slave_buswidth width; unsigned es; u32 burst; void __iomem *chstat_reg; void __iomem *irqstat_reg; int wait_res; mcspi = spi_master_get_devdata(spi->master); mcspi_dma = &mcspi->dma_channels[spi->chip_select]; l = mcspi_cached_chconf0(spi); if (cs->word_len <= 8) { width = DMA_SLAVE_BUSWIDTH_1_BYTE; es = 1; } else if (cs->word_len <= 16) { width = DMA_SLAVE_BUSWIDTH_2_BYTES; es = 2; } else { width = DMA_SLAVE_BUSWIDTH_4_BYTES; es = 4; } count = xfer->len; burst = 1; if (mcspi->fifo_depth > 0) { if (count > mcspi->fifo_depth) burst = mcspi->fifo_depth / es; else burst = count / es; } memset(&cfg, 0, sizeof(cfg)); cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0; cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0; cfg.src_addr_width = width; cfg.dst_addr_width = width; cfg.src_maxburst = burst; cfg.dst_maxburst = burst; rx = xfer->rx_buf; tx = xfer->tx_buf; if (tx != NULL) omap2_mcspi_tx_dma(spi, xfer, cfg); if (rx != NULL) count = omap2_mcspi_rx_dma(spi, xfer, cfg, es); if (tx != NULL) { wait_for_completion(&mcspi_dma->dma_tx_completion); if (mcspi->fifo_depth > 0) { irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS; if (mcspi_wait_for_reg_bit(irqstat_reg, OMAP2_MCSPI_IRQSTATUS_EOW) < 0) dev_err(&spi->dev, "EOW timed out\n"); mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS, OMAP2_MCSPI_IRQSTATUS_EOW); } /* for TX_ONLY mode, be sure all words have shifted out */ if (rx == NULL) { chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0; if (mcspi->fifo_depth > 0) { wait_res = mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_TXFFE); if (wait_res < 0) dev_err(&spi->dev, "TXFFE timed out\n"); } else { wait_res = mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_TXS); if (wait_res < 0) dev_err(&spi->dev, "TXS timed out\n"); } if (wait_res >= 0 && (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_EOT) < 0)) dev_err(&spi->dev, "EOT timed out\n"); } } return count; } static unsigned omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer) { struct omap2_mcspi *mcspi; struct omap2_mcspi_cs *cs = spi->controller_state; unsigned int count, c; u32 l; void __iomem *base = cs->base; void __iomem *tx_reg; void __iomem *rx_reg; void __iomem *chstat_reg; int word_len; mcspi = spi_master_get_devdata(spi->master); count = xfer->len; c = count; word_len = cs->word_len; l = mcspi_cached_chconf0(spi); /* We store the pre-calculated register addresses on stack to speed * up the transfer loop. */ tx_reg = base + OMAP2_MCSPI_TX0; rx_reg = base + OMAP2_MCSPI_RX0; chstat_reg = base + OMAP2_MCSPI_CHSTAT0; if (c < (word_len>>3)) return 0; if (word_len <= 8) { u8 *rx; const u8 *tx; rx = xfer->rx_buf; tx = xfer->tx_buf; do { c -= 1; if (tx != NULL) { if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_TXS) < 0) { dev_err(&spi->dev, "TXS timed out\n"); goto out; } dev_vdbg(&spi->dev, "write-%d %02x\n", word_len, *tx); writel_relaxed(*tx++, tx_reg); } if (rx != NULL) { if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS) < 0) { dev_err(&spi->dev, "RXS timed out\n"); goto out; } if (c == 1 && tx == NULL && (l & OMAP2_MCSPI_CHCONF_TURBO)) { omap2_mcspi_set_enable(spi, 0); *rx++ = readl_relaxed(rx_reg); dev_vdbg(&spi->dev, "read-%d %02x\n", word_len, *(rx - 1)); if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS) < 0) { dev_err(&spi->dev, "RXS timed out\n"); goto out; } c = 0; } else if (c == 0 && tx == NULL) { omap2_mcspi_set_enable(spi, 0); } *rx++ = readl_relaxed(rx_reg); dev_vdbg(&spi->dev, "read-%d %02x\n", word_len, *(rx - 1)); } } while (c); } else if (word_len <= 16) { u16 *rx; const u16 *tx; rx = xfer->rx_buf; tx = xfer->tx_buf; do { c -= 2; if (tx != NULL) { if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_TXS) < 0) { dev_err(&spi->dev, "TXS timed out\n"); goto out; } dev_vdbg(&spi->dev, "write-%d %04x\n", word_len, *tx); writel_relaxed(*tx++, tx_reg); } if (rx != NULL) { if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS) < 0) { dev_err(&spi->dev, "RXS timed out\n"); goto out; } if (c == 2 && tx == NULL && (l & OMAP2_MCSPI_CHCONF_TURBO)) { omap2_mcspi_set_enable(spi, 0); *rx++ = readl_relaxed(rx_reg); dev_vdbg(&spi->dev, "read-%d %04x\n", word_len, *(rx - 1)); if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS) < 0) { dev_err(&spi->dev, "RXS timed out\n"); goto out; } c = 0; } else if (c == 0 && tx == NULL) { omap2_mcspi_set_enable(spi, 0); } *rx++ = readl_relaxed(rx_reg); dev_vdbg(&spi->dev, "read-%d %04x\n", word_len, *(rx - 1)); } } while (c >= 2); } else if (word_len <= 32) { u32 *rx; const u32 *tx; rx = xfer->rx_buf; tx = xfer->tx_buf; do { c -= 4; if (tx != NULL) { if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_TXS) < 0) { dev_err(&spi->dev, "TXS timed out\n"); goto out; } dev_vdbg(&spi->dev, "write-%d %08x\n", word_len, *tx); writel_relaxed(*tx++, tx_reg); } if (rx != NULL) { if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS) < 0) { dev_err(&spi->dev, "RXS timed out\n"); goto out; } if (c == 4 && tx == NULL && (l & OMAP2_MCSPI_CHCONF_TURBO)) { omap2_mcspi_set_enable(spi, 0); *rx++ = readl_relaxed(rx_reg); dev_vdbg(&spi->dev, "read-%d %08x\n", word_len, *(rx - 1)); if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS) < 0) { dev_err(&spi->dev, "RXS timed out\n"); goto out; } c = 0; } else if (c == 0 && tx == NULL) { omap2_mcspi_set_enable(spi, 0); } *rx++ = readl_relaxed(rx_reg); dev_vdbg(&spi->dev, "read-%d %08x\n", word_len, *(rx - 1)); } } while (c >= 4); } /* for TX_ONLY mode, be sure all words have shifted out */ if (xfer->rx_buf == NULL) { if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_TXS) < 0) { dev_err(&spi->dev, "TXS timed out\n"); } else if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_EOT) < 0) dev_err(&spi->dev, "EOT timed out\n"); /* disable chan to purge rx datas received in TX_ONLY transfer, * otherwise these rx datas will affect the direct following * RX_ONLY transfer. */ omap2_mcspi_set_enable(spi, 0); } out: omap2_mcspi_set_enable(spi, 1); return count - c; } static u32 omap2_mcspi_calc_divisor(u32 speed_hz) { u32 div; for (div = 0; div < 15; div++) if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div)) return div; return 15; } /* called only when no transfer is active to this device */ static int omap2_mcspi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) { struct omap2_mcspi_cs *cs = spi->controller_state; struct omap2_mcspi *mcspi; struct spi_master *spi_cntrl; u32 l = 0, clkd = 0, div, extclk = 0, clkg = 0; u8 word_len = spi->bits_per_word; u32 speed_hz = spi->max_speed_hz; mcspi = spi_master_get_devdata(spi->master); spi_cntrl = mcspi->master; if (t != NULL && t->bits_per_word) word_len = t->bits_per_word; cs->word_len = word_len; if (t && t->speed_hz) speed_hz = t->speed_hz; speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ); if (speed_hz < (OMAP2_MCSPI_MAX_FREQ / OMAP2_MCSPI_MAX_DIVIDER)) { clkd = omap2_mcspi_calc_divisor(speed_hz); speed_hz = OMAP2_MCSPI_MAX_FREQ >> clkd; clkg = 0; } else { div = (OMAP2_MCSPI_MAX_FREQ + speed_hz - 1) / speed_hz; speed_hz = OMAP2_MCSPI_MAX_FREQ / div; clkd = (div - 1) & 0xf; extclk = (div - 1) >> 4; clkg = OMAP2_MCSPI_CHCONF_CLKG; } l = mcspi_cached_chconf0(spi); /* standard 4-wire master mode: SCK, MOSI/out, MISO/in, nCS * REVISIT: this controller could support SPI_3WIRE mode. */ if (mcspi->pin_dir == MCSPI_PINDIR_D0_IN_D1_OUT) { l &= ~OMAP2_MCSPI_CHCONF_IS; l &= ~OMAP2_MCSPI_CHCONF_DPE1; l |= OMAP2_MCSPI_CHCONF_DPE0; } else { l |= OMAP2_MCSPI_CHCONF_IS; l |= OMAP2_MCSPI_CHCONF_DPE1; l &= ~OMAP2_MCSPI_CHCONF_DPE0; } /* wordlength */ l &= ~OMAP2_MCSPI_CHCONF_WL_MASK; l |= (word_len - 1) << 7; /* set chipselect polarity; manage with FORCE */ if (!(spi->mode & SPI_CS_HIGH)) l |= OMAP2_MCSPI_CHCONF_EPOL; /* active-low; normal */ else l &= ~OMAP2_MCSPI_CHCONF_EPOL; /* set clock divisor */ l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK; l |= clkd << 2; /* set clock granularity */ l &= ~OMAP2_MCSPI_CHCONF_CLKG; l |= clkg; if (clkg) { cs->chctrl0 &= ~OMAP2_MCSPI_CHCTRL_EXTCLK_MASK; cs->chctrl0 |= extclk << 8; mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0); } /* set SPI mode 0..3 */ if (spi->mode & SPI_CPOL) l |= OMAP2_MCSPI_CHCONF_POL; else l &= ~OMAP2_MCSPI_CHCONF_POL; if (spi->mode & SPI_CPHA) l |= OMAP2_MCSPI_CHCONF_PHA; else l &= ~OMAP2_MCSPI_CHCONF_PHA; mcspi_write_chconf0(spi, l); cs->mode = spi->mode; dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n", speed_hz, (spi->mode & SPI_CPHA) ? "trailing" : "leading", (spi->mode & SPI_CPOL) ? "inverted" : "normal"); return 0; } /* * Note that we currently allow DMA only if we get a channel * for both rx and tx. Otherwise we'll do PIO for both rx and tx. */ static int omap2_mcspi_request_dma(struct spi_device *spi) { struct spi_master *master = spi->master; struct omap2_mcspi *mcspi; struct omap2_mcspi_dma *mcspi_dma; int ret = 0; mcspi = spi_master_get_devdata(master); mcspi_dma = mcspi->dma_channels + spi->chip_select; init_completion(&mcspi_dma->dma_rx_completion); init_completion(&mcspi_dma->dma_tx_completion); mcspi_dma->dma_rx = dma_request_chan(&master->dev, mcspi_dma->dma_rx_ch_name); if (IS_ERR(mcspi_dma->dma_rx)) { ret = PTR_ERR(mcspi_dma->dma_rx); mcspi_dma->dma_rx = NULL; goto no_dma; } mcspi_dma->dma_tx = dma_request_chan(&master->dev, mcspi_dma->dma_tx_ch_name); if (IS_ERR(mcspi_dma->dma_tx)) { ret = PTR_ERR(mcspi_dma->dma_tx); mcspi_dma->dma_tx = NULL; dma_release_channel(mcspi_dma->dma_rx); mcspi_dma->dma_rx = NULL; } no_dma: return ret; } static int omap2_mcspi_setup(struct spi_device *spi) { int ret; struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master); struct omap2_mcspi_regs *ctx = &mcspi->ctx; struct omap2_mcspi_dma *mcspi_dma; struct omap2_mcspi_cs *cs = spi->controller_state; mcspi_dma = &mcspi->dma_channels[spi->chip_select]; if (!cs) { cs = kzalloc(sizeof *cs, GFP_KERNEL); if (!cs) return -ENOMEM; cs->base = mcspi->base + spi->chip_select * 0x14; cs->phys = mcspi->phys + spi->chip_select * 0x14; cs->mode = 0; cs->chconf0 = 0; cs->chctrl0 = 0; spi->controller_state = cs; /* Link this to context save list */ list_add_tail(&cs->node, &ctx->cs); if (gpio_is_valid(spi->cs_gpio)) { ret = gpio_request(spi->cs_gpio, dev_name(&spi->dev)); if (ret) { dev_err(&spi->dev, "failed to request gpio\n"); return ret; } gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH)); } } if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) { ret = omap2_mcspi_request_dma(spi); if (ret) dev_warn(&spi->dev, "not using DMA for McSPI (%d)\n", ret); } ret = pm_runtime_get_sync(mcspi->dev); if (ret < 0) { pm_runtime_put_noidle(mcspi->dev); return ret; } ret = omap2_mcspi_setup_transfer(spi, NULL); pm_runtime_mark_last_busy(mcspi->dev); pm_runtime_put_autosuspend(mcspi->dev); return ret; } static void omap2_mcspi_cleanup(struct spi_device *spi) { struct omap2_mcspi *mcspi; struct omap2_mcspi_dma *mcspi_dma; struct omap2_mcspi_cs *cs; mcspi = spi_master_get_devdata(spi->master); if (spi->controller_state) { /* Unlink controller state from context save list */ cs = spi->controller_state; list_del(&cs->node); kfree(cs); } if (spi->chip_select < spi->master->num_chipselect) { mcspi_dma = &mcspi->dma_channels[spi->chip_select]; if (mcspi_dma->dma_rx) { dma_release_channel(mcspi_dma->dma_rx); mcspi_dma->dma_rx = NULL; } if (mcspi_dma->dma_tx) { dma_release_channel(mcspi_dma->dma_tx); mcspi_dma->dma_tx = NULL; } } if (gpio_is_valid(spi->cs_gpio)) gpio_free(spi->cs_gpio); } static int omap2_mcspi_transfer_one(struct spi_master *master, struct spi_device *spi, struct spi_transfer *t) { /* We only enable one channel at a time -- the one whose message is * -- although this controller would gladly * arbitrate among multiple channels. This corresponds to "single * channel" master mode. As a side effect, we need to manage the * chipselect with the FORCE bit ... CS != channel enable. */ struct omap2_mcspi *mcspi; struct omap2_mcspi_dma *mcspi_dma; struct omap2_mcspi_cs *cs; struct omap2_mcspi_device_config *cd; int par_override = 0; int status = 0; u32 chconf; mcspi = spi_master_get_devdata(master); mcspi_dma = mcspi->dma_channels + spi->chip_select; cs = spi->controller_state; cd = spi->controller_data; /* * The slave driver could have changed spi->mode in which case * it will be different from cs->mode (the current hardware setup). * If so, set par_override (even though its not a parity issue) so * omap2_mcspi_setup_transfer will be called to configure the hardware * with the correct mode on the first iteration of the loop below. */ if (spi->mode != cs->mode) par_override = 1; omap2_mcspi_set_enable(spi, 0); if (gpio_is_valid(spi->cs_gpio)) omap2_mcspi_set_cs(spi, spi->mode & SPI_CS_HIGH); if (par_override || (t->speed_hz != spi->max_speed_hz) || (t->bits_per_word != spi->bits_per_word)) { par_override = 1; status = omap2_mcspi_setup_transfer(spi, t); if (status < 0) goto out; if (t->speed_hz == spi->max_speed_hz && t->bits_per_word == spi->bits_per_word) par_override = 0; } if (cd && cd->cs_per_word) { chconf = mcspi->ctx.modulctrl; chconf &= ~OMAP2_MCSPI_MODULCTRL_SINGLE; mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf); mcspi->ctx.modulctrl = mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL); } chconf = mcspi_cached_chconf0(spi); chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK; chconf &= ~OMAP2_MCSPI_CHCONF_TURBO; if (t->tx_buf == NULL) chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY; else if (t->rx_buf == NULL) chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY; if (cd && cd->turbo_mode && t->tx_buf == NULL) { /* Turbo mode is for more than one word */ if (t->len > ((cs->word_len + 7) >> 3)) chconf |= OMAP2_MCSPI_CHCONF_TURBO; } mcspi_write_chconf0(spi, chconf); if (t->len) { unsigned count; if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) && master->cur_msg_mapped && master->can_dma(master, spi, t)) omap2_mcspi_set_fifo(spi, t, 1); omap2_mcspi_set_enable(spi, 1); /* RX_ONLY mode needs dummy data in TX reg */ if (t->tx_buf == NULL) writel_relaxed(0, cs->base + OMAP2_MCSPI_TX0); if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) && master->cur_msg_mapped && master->can_dma(master, spi, t)) count = omap2_mcspi_txrx_dma(spi, t); else count = omap2_mcspi_txrx_pio(spi, t); if (count != t->len) { status = -EIO; goto out; } } omap2_mcspi_set_enable(spi, 0); if (mcspi->fifo_depth > 0) omap2_mcspi_set_fifo(spi, t, 0); out: /* Restore defaults if they were overriden */ if (par_override) { par_override = 0; status = omap2_mcspi_setup_transfer(spi, NULL); } if (cd && cd->cs_per_word) { chconf = mcspi->ctx.modulctrl; chconf |= OMAP2_MCSPI_MODULCTRL_SINGLE; mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf); mcspi->ctx.modulctrl = mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL); } omap2_mcspi_set_enable(spi, 0); if (gpio_is_valid(spi->cs_gpio)) omap2_mcspi_set_cs(spi, !(spi->mode & SPI_CS_HIGH)); if (mcspi->fifo_depth > 0 && t) omap2_mcspi_set_fifo(spi, t, 0); return status; } static int omap2_mcspi_prepare_message(struct spi_master *master, struct spi_message *msg) { struct omap2_mcspi *mcspi = spi_master_get_devdata(master); struct omap2_mcspi_regs *ctx = &mcspi->ctx; struct omap2_mcspi_cs *cs; /* Only a single channel can have the FORCE bit enabled * in its chconf0 register. * Scan all channels and disable them except the current one. * A FORCE can remain from a last transfer having cs_change enabled */ list_for_each_entry(cs, &ctx->cs, node) { if (msg->spi->controller_state == cs) continue; if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE)) { cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE; writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0); readl_relaxed(cs->base + OMAP2_MCSPI_CHCONF0); } } return 0; } static bool omap2_mcspi_can_dma(struct spi_master *master, struct spi_device *spi, struct spi_transfer *xfer) { return (xfer->len >= DMA_MIN_BYTES); } static int omap2_mcspi_master_setup(struct omap2_mcspi *mcspi) { struct spi_master *master = mcspi->master; struct omap2_mcspi_regs *ctx = &mcspi->ctx; int ret = 0; ret = pm_runtime_get_sync(mcspi->dev); if (ret < 0) { pm_runtime_put_noidle(mcspi->dev); return ret; } mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE, OMAP2_MCSPI_WAKEUPENABLE_WKEN); ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN; omap2_mcspi_set_master_mode(master); pm_runtime_mark_last_busy(mcspi->dev); pm_runtime_put_autosuspend(mcspi->dev); return 0; } /* * When SPI wake up from off-mode, CS is in activate state. If it was in * inactive state when driver was suspend, then force it to inactive state at * wake up. */ static int omap_mcspi_runtime_resume(struct device *dev) { struct spi_master *master = dev_get_drvdata(dev); struct omap2_mcspi *mcspi = spi_master_get_devdata(master); struct omap2_mcspi_regs *ctx = &mcspi->ctx; struct omap2_mcspi_cs *cs; /* McSPI: context restore */ mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, ctx->modulctrl); mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE, ctx->wakeupenable); list_for_each_entry(cs, &ctx->cs, node) { /* * We need to toggle CS state for OMAP take this * change in account. */ if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) { cs->chconf0 |= OMAP2_MCSPI_CHCONF_FORCE; writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0); cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE; writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0); } else { writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0); } } return 0; } static struct omap2_mcspi_platform_config omap2_pdata = { .regs_offset = 0, }; static struct omap2_mcspi_platform_config omap4_pdata = { .regs_offset = OMAP4_MCSPI_REG_OFFSET, }; static const struct of_device_id omap_mcspi_of_match[] = { { .compatible = "ti,omap2-mcspi", .data = &omap2_pdata, }, { .compatible = "ti,omap4-mcspi", .data = &omap4_pdata, }, { }, }; MODULE_DEVICE_TABLE(of, omap_mcspi_of_match); static int omap2_mcspi_probe(struct platform_device *pdev) { struct spi_master *master; const struct omap2_mcspi_platform_config *pdata; struct omap2_mcspi *mcspi; struct resource *r; int status = 0, i; u32 regs_offset = 0; struct device_node *node = pdev->dev.of_node; const struct of_device_id *match; master = spi_alloc_master(&pdev->dev, sizeof *mcspi); if (master == NULL) { dev_dbg(&pdev->dev, "master allocation failed\n"); return -ENOMEM; } /* the spi->mode bits understood by this driver: */ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32); master->setup = omap2_mcspi_setup; master->auto_runtime_pm = true; master->prepare_message = omap2_mcspi_prepare_message; master->can_dma = omap2_mcspi_can_dma; master->transfer_one = omap2_mcspi_transfer_one; master->set_cs = omap2_mcspi_set_cs; master->cleanup = omap2_mcspi_cleanup; master->dev.of_node = node; master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ; master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15; platform_set_drvdata(pdev, master); mcspi = spi_master_get_devdata(master); mcspi->master = master; match = of_match_device(omap_mcspi_of_match, &pdev->dev); if (match) { u32 num_cs = 1; /* default number of chipselect */ pdata = match->data; of_property_read_u32(node, "ti,spi-num-cs", &num_cs); master->num_chipselect = num_cs; if (of_get_property(node, "ti,pindir-d0-out-d1-in", NULL)) mcspi->pin_dir = MCSPI_PINDIR_D0_OUT_D1_IN; } else { pdata = dev_get_platdata(&pdev->dev); master->num_chipselect = pdata->num_cs; mcspi->pin_dir = pdata->pin_dir; } regs_offset = pdata->regs_offset; r = platform_get_resource(pdev, IORESOURCE_MEM, 0); mcspi->base = devm_ioremap_resource(&pdev->dev, r); if (IS_ERR(mcspi->base)) { status = PTR_ERR(mcspi->base); goto free_master; } mcspi->phys = r->start + regs_offset; mcspi->base += regs_offset; mcspi->dev = &pdev->dev; INIT_LIST_HEAD(&mcspi->ctx.cs); mcspi->dma_channels = devm_kcalloc(&pdev->dev, master->num_chipselect, sizeof(struct omap2_mcspi_dma), GFP_KERNEL); if (mcspi->dma_channels == NULL) { status = -ENOMEM; goto free_master; } for (i = 0; i < master->num_chipselect; i++) { sprintf(mcspi->dma_channels[i].dma_rx_ch_name, "rx%d", i); sprintf(mcspi->dma_channels[i].dma_tx_ch_name, "tx%d", i); } pm_runtime_use_autosuspend(&pdev->dev); pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT); pm_runtime_enable(&pdev->dev); status = omap2_mcspi_master_setup(mcspi); if (status < 0) goto disable_pm; status = devm_spi_register_master(&pdev->dev, master); if (status < 0) goto disable_pm; return status; disable_pm: pm_runtime_dont_use_autosuspend(&pdev->dev); pm_runtime_put_sync(&pdev->dev); pm_runtime_disable(&pdev->dev); free_master: spi_master_put(master); return status; } static int omap2_mcspi_remove(struct platform_device *pdev) { struct spi_master *master = platform_get_drvdata(pdev); struct omap2_mcspi *mcspi = spi_master_get_devdata(master); pm_runtime_dont_use_autosuspend(mcspi->dev); pm_runtime_put_sync(mcspi->dev); pm_runtime_disable(&pdev->dev); return 0; } /* work with hotplug and coldplug */ MODULE_ALIAS("platform:omap2_mcspi"); #ifdef CONFIG_SUSPEND static int omap2_mcspi_suspend_noirq(struct device *dev) { return pinctrl_pm_select_sleep_state(dev); } static int omap2_mcspi_resume_noirq(struct device *dev) { struct spi_master *master = dev_get_drvdata(dev); struct omap2_mcspi *mcspi = spi_master_get_devdata(master); int error; error = pinctrl_pm_select_default_state(dev); if (error) dev_warn(mcspi->dev, "%s: failed to set pins: %i\n", __func__, error); return 0; } #else #define omap2_mcspi_suspend_noirq NULL #define omap2_mcspi_resume_noirq NULL #endif static const struct dev_pm_ops omap2_mcspi_pm_ops = { .suspend_noirq = omap2_mcspi_suspend_noirq, .resume_noirq = omap2_mcspi_resume_noirq, .runtime_resume = omap_mcspi_runtime_resume, }; static struct platform_driver omap2_mcspi_driver = { .driver = { .name = "omap2_mcspi", .pm = &omap2_mcspi_pm_ops, .of_match_table = omap_mcspi_of_match, }, .probe = omap2_mcspi_probe, .remove = omap2_mcspi_remove, }; module_platform_driver(omap2_mcspi_driver); MODULE_LICENSE("GPL");